By: Joseph Feste, M.D., FACOG, AACS, AACG, Medical Director

Progesterone and Breast Cancer

Unfortunately, no one knows the exact cause of breast cancer and there are many theories as to why a woman might get breast cancer. What makes the disease so tragic is that it can affect women at a young age in contrast to some of the other cancers which occur later on in life.

We see patients every day in our clinics in Austin, San Antonio and College Station who suffer from progesterone deficiencies. Most are unaware that a progesterone deficiency can be a major cause or contributing factor to the development of breast cancer, either directly or indirectly. However, they seek biodentical hormone therapy to address various symptoms and soon learn the many benefits of bioidentical progesterone. Some have read Suzanne Somers’s book on Bioidentical Hormone Therapy and her bout with breast cancer.

Five miscarriages and family history of breast cancer.

One of our patients explained she was searching for bioidentical hormone therapy in San Antonio because of her history of five miscarriages. She advised us that she had a family history of breast cancer (four females in her family had suffered with breast cancer). Not one of her primary care doctors seemed to connect her miscarriages with her family history of breast cancer or even to progesterone. Yet the common factor is low progesterone.

Her mother and sisters, like her, suffered from difficult periods and her mother and two sisters had hysterectomies – all signs of low progesterone. She could not carry a baby to term and she has nightmarish periods. She also struggled with her weight and PMS.

I am happy to say that after treatment with progesterone, she went on to have a healthy baby girl and no longer fears breast cancer as she once did. Her periods are now regulated with bioidentical progesterone and she has gained significant protection against the risk of breast cancer.

A client in College Station mentioned today that her sister had five miscarriages under the care of one physician. She changed physicians and had a healthy baby boy after the new physician prescribed progesterone. We do this on a consistent basis in our clinics.

Patient diagnosed with BRCA I gene who had a full mastectomy.

S.B is a 45 year old female who had a diagnosis of BRCA1 breast cancer in 2004. She was treated with a total bilateral mastectomy, chemotherapy and radiation therapy. In 2006, she had her ovaries removed because it was the standard protocol for BRCA1 breast cancers. Her surgeon left the uterus.

She came to see us (ten years after her original surgery) stating she was miserable and suffered from hot flashes, night sweats, total loss of libido, insomnia and all other signs and symptoms of testosterone, progesterone and estrogen deficiency. Her lab tests verified the absence of these hormones as well as a low thyroid function.

Her original treating doctors refused to prescribe her any hormones regardless of her symptoms and her pleas. She came to see Dr. Feste to obtain relief. Dr. Feste explained to her that contrary to what she had been told, studies show that estrogen does not cause breast cancer. This was shown in the WHI study and other more recent studies. It has also been shown that progesterone deficiency is linked to the cancer as is taking a synthetic progestin.

In fact, studies show that after five years of being cancer free, women can enjoy the 400 benefits of estrogen just like other post-menopausal women. Science has also shown that women on HRT who have had breast cancer do better than the women not taking HRT if there is a recurrence.

At Natural Bio Health, all women on estradiol also take progesterone to keep these two important hormones complimenting each other.

Is cancer a risk for S.B.?

Because there are many different contributing causes to cancer (see below), you cannot say that a person may never get a particular form of cancer. However, in S.B.’s case, she has no breasts as they were removed in 2004; her lymph nodes are negative for cancer; the tumor was confined to the breast; and she has been cancer free for over 10 years.

Dr. Feste agreed that she deserved to feel better as her quality of life was almost intolerable. The science of hormones did not support her treating doctor’s conclusions that she was sentenced to a life of misery.

She has now started on bio identical estrogen, progesterone, testosterone and thyroid. She will be followed on a regular basis and will have blood tests to keep her hormone levels consistent with a patient who is post-menopausal. Her hot flashes and night sweats will soon be a thing of the past and she will regain her sex drive and quality of life.

The Science on BRCA1 and BRCA2 and family history of breast cancer.

A small percentage of women have a BRCA1 or BRCA2 gene that makes them genetically prone to breast cancer. However, studies show that breast cancer can more often be linked to low progesterone levels. The studies on the relationship between breast cancer and progesterone are legion. With the exception of BRCA1 or 2, a family history does not mean you are more likely to get cancer of the breast.

JNCT Journal of the National Cancer Institute 2000: 100 (19) 1361-1367 Among postmenopausal women with a BRCA1 mutation, HT use was not associated with increased risk of breast cancer; indeed, in this population, it was associated with a decreased risk.

The risk of developing breast cancer due to taking hormone replacement therapy appears to be the same for women with a family history of the disease and without a family history. It also refutes the notion, held by many in the medical community, that a familial predisposition to breast cancer enhances the carcinogenic effects of estrogen.

The above study suggests that causal pathway based on family history is probably not estrogen. Gramling R, Eaton CB, Rothman KJ, et al. Hormone Replacement Therapy, Family History, and Breast Cancer Risk Among Postmenopausal Women. Epidemiology.2009 Sep;20(5):752-756.

For a free consultation to discuss the Austin Bioidentical Hormone Therapy program or the San Antonio Bioidentical Hormone Therapy program, go to www.naturalbiohealth.com. College Station Bioidentical Hormone Therapy program also available.